Derrick structure



'Sept. 24, 1940. FRANKs 2,215,920

DERRICK STRUCTURE Filed Aug. 12, 1938 3 Sheets-Sheet l v INVENTOR HAKKY H NKs z ATTORNEY q 24, 1940- H. H. FRANKS I DERRICK STRUCTURE a Sheetis-Sheet 2 Filed Aug. 12, 1938 INVENTOR HARRY b4 kA/VKS ATTORNEY s it. 24, 1940.

H. H. FRANKS DERRICK STRUCTURE Filed Aug. 12, 1938 3 Sheets-Sheet 3 INVENTOR f flmr 6 Fiend/ 5 BY ATTORNEY Patented Sept. 24, 1940 PATENT OFFICE DERRICK STRUCTURE HarryH. Franks, Tulsa,

Okla., assignor to Franks Manufacturing Corporation, Tulsa, Okla, a corporation of Oklahoma Application August 12, 1938, Serial No. 224,513

1 Claim.

This invention relates to derrick structures and particularly to portable type derricks which are adapted to be quickly and easily folded or col- I lapsed into a compact form suitable for conveni- 5 ent transportation from place to place.

The development or such portable drilling rigs has proceeded at such a rapid pace thatthey have now been designed and actually employed successfully to drill wells ranging in depth to 5,000 feet, or more. Such deep drilling requires, among other necessary equipment, relatively tall and'heavy derricks in order to handle the long and heavy strings of drill pipe and casing necessitated by such deep wells. Derricks, as much as ninety feet in height and of great strength are required, and such derricks, exclusive of auxiliary equipment, will weigh many thousands of pounds. Since almost all states have formulated laws and regulations greatly limiting the horizontal and vertical dimensions of structures which may be transported over their highways, obviously, it has become an important problem to construct a form of derrick large enough for deep drilling but which may be mounted on a transporting vehicle scribed by such laws and regulations.

The base dimensions of derricks of the height above indicated are generally such that when the derrick is in horizontal transport position, the height above the ground level will exceed the various state regulations and 'so must be restricted, and this invention contemplates a derrick structure having a lower or base section, the front and rear panels of which may be folded together into a comparatively fiat structure when moved to transport position, and expanded to full base dimensions when raised to operating position, and which will be limited in length, but adapted 'to receive additional upper sections, when in operating position, in order'to increase its length to any length desired to meet particular drilling conditions.

Therefore, a principal object of this to provide a new form of derrick structure which may be pivotally mounted on a transport base and which maybe folded for transporting into a. structure of reduced dimensions.

Another object is to provide a portable derrick structure which folds upon itself when lowered to and yet kept within the dimensional limits preinvention is a transport position and which unfolds when derrick is lowered to transport position and expanded to full dimensions when raised to operating position.

Another object is to provide a portable, folding derrick base member upon which additional derrick sections may be assembled to provide a structure of any desired height.

Still another object is to provide a folding derrick structure having one pair of its corner legs constructed in the form of cantilever trusses pivotally mounted on a supporting base.

Other and more specific objects and advantages will become apparent from the following description and the accompanying drawings which illustrate one form of derrick structure in accord-- ance with this invention.

In the drawings:

Fig. 1 is a side view showing the derrick structure of this invention mounted on a transporting vehicle. The derrick base member is shown in vertical operating position in full lines, the top portion thereof being in dotted lines, and partially lowered toward transport position in dotted outlines.

' Fig. 2 is an enlarged side view of the lower portion of .the structure shown in Fig. 1.

Fig. 3 is an end view of the portion of the structure shown in Fig. 2.

\ Figs. 4 and 5 aredetails of one of the hinge connections between one of the derrick legs and one of the connecting girders.

Fig. 6 is a horizontal section taken along line 6 -6 of Fig. 4.

Referringto the drawings, and to Fig. 1 in this invention, and designated generally by the numeral I, is shown mounted on a frame 2 which is in turn mounted on a mobile base such as trailer 3. The transport vehicle may also be an I automobile truck or skids as desired. The derrick I is pivotally mounted on a frame 2 by means of hinge bar 4 extending horizontally between oppoparticular, a derrick structure in accordance with site side members of the derrick and rotatively supported on upright members 5 carried by frame 2 and extending upwardly therefrom. The derrick structure is raised and lowered between oper- 8 ating and transport positions about hinge bar 4 by means of a pitman 6 which has one end rotatively attached to the lower end of derrick l and the other journalled in a cross head memher 1 which is longitudinally movable in an outer 10 guideway of frame 2.

The derrick structure I includes front legs 88, preferably though not necessarily of tubular construction, which are spaced apart a distance suitable for the particular derrick desired, but ordi- 15 narily are less than eight feet apart, since this distance is the width limit generally prescribed by highway laws and regulations. The legs 8-8, preferably slope inwardly toward the vertical axis of the derrick. The rear legs of the derrick, designated generally by the numerals 99, comprise structures in the form of cantilever trusses,

the front stringers Ill-l being parallel to front legs 88 and the rear stringers ll-il sloping toward the vertical axis of the derrick oppositely to front legs 8-8 and at substantially the same angle, with the result that stringers l0 and II of each truss meet at an acute angle at a point toward the upper portion of the derrick. The point vat which the stringers meet depends, of course,

upon the angle between them, and this is determined by-the length and size of each particular derrick. The stringers i0 and II of each truss are also of tubular construction and are strongly 35 cross braced by bracing members l2 thus completing the truss structures.

Each front leg 8 is hingedly connected to the adjacent stringer Ill on the same side of the derrick by a plurality of vertically spaced, horizontal girders iii. The opposite ends of each-of o girders I3 is connected by hinge connections, de-

noted generally by the numerals l4-ll, to the front leg 8 and its corresponding stringer ill. Front legs 8-8 are spaced. apart and rigidly connected together by means of girders l5 and braces l6, forming the front panel of the derrick structure (Fig. 3), while stringers ll-i l are likewise spacedapart and rigidly connected to each other by similar girders and braces to form the rear panel of the derrick structure. Since legs 88 and stringers l0i0 are parallel, all of the girders l3 will be equal in length, and the purpose of this arrangement will be explained in greater detail hereinafter.

The portion of the derrick structure which includes the trusses 99 and ront legs 8-8 forms a derrick base member, upon the upper part of which a superstructure S, consisting of additional derrick sections, crown block, platform, etc., may

60 be manually superimposed to increase the over- 70 I4 is shown in detail in Figs. .4 to 6, inclusive, and

consists of a hollow sleeve II which extends transversely through the end of girder l3, which.

is preferably of tubular construction because of the greater strength of such construction. Sleeve 75 I1 is slightly longer the diameter of girder ating position, the structure is firmly braced be- II and its ends project from each side of girder It, to which sleeve I1 is rigidly welded. A second hollow sleeve I8 is mounted within the bore of sleeve l1 and is closely fitting therein, being inserted therein ordinarily by pressing or driv- 5 ing. Sleeve I8 is longer than sleeve l1 and positioned therein so that its ends project from each end of sleeve I! to form hollow trunnions l9 which are journalled in registering circular openings 2ll 20 provided in a pair of connector plates 10 2l-2l, which are welded or otherwise rigidly attached to opposite sides of one of the legs 8-4! or stringers ill-Ill, depending upon which end of girder I3 is being considered.

In assembling girder l3 to legs 8 and stringer III by means of the hinge connection ll, an end of the girder carrying sleeve I! only, is inserted between plates 2l2i with the bore of sleeve I1 in registration with openings 28-40, and then sleeve I8 is inserted through one of the openings 20 and the bore of sleeve ll until the other end of sleeve I8 is received in the opposite opening 20, thus completing the hinge connection of the girder to either the leg 8 or stringer III as the case may be. The projecting ends of sleeve H, which are larger than the diameter of openings 20, act as spacers between plates 2 I-2 I When the derrick structure is in vertical opertween the legs 8 and the corresponding stringers l0 by means of cross braces 22, shown in dotted outlines in Fig. 1 and fragmentarily, in full lines,

in Figs. 4 to 6, which extend between diagonally opposite hinge connections II and are connected thereto by means of bolts 23 which are inserted through the bores of sleeves l8 and through appropriate openings in the ends of cross braces 22. Two cross braces 22 are connected to each hinge connection I! at opposite sides thereof, one of the cross braces extending downwardly and the other upwardly, as illustrated in detail in Figs.

Legs 8-8 and stringers I l--l I, which form the comer posts of the derrick, are provided with adjustable 'feet 24- -24 for leveling the corners of the derrick when in operating position.

The operation of the above described derrick structure is as follows:

Starting with the derrick in vertical operating 0 position, with cross braces 22 and superstructure S in place, it is desired to lower the derrick to transport position. superstructure S and cross braces 22 are first removed from the more permament portions of the structure and by moving .cross head I toward the rear end of frame 2,

(considering the derrick to be mounted on the rear end of frame 2) -pitman 8 applies a thrust against the lower extremity of the derrick, which causes the derrick to rotate about pivot bar 4, the upper portion of the derrick coming to rest finally on the forward portion of the transport vehicle, as shown in dotted outlines in Figs. 1 and 2 particularly. As the derrick swings rearwardly from its vertical position, the hinged connections of girders." between legs 8 and stringers ill permits the front panel of the derrick to slide downwardly relative to the rear panel of the derrick and parallel thereto and assume a final position immediately adjacent to, and superimposed on stringers 7 II, as shown in dotted outlines in Fig. 2. By making stringers III and legs 8 parallel to each other, and thereby making girders ll of equal length, legs 8 and stringers l0 maintain their parallelism throughout the lowering operation,

and thus permit theiront panel to, fold down completely on stringers l0. As a result the maximum dimension of the structure, when in transport position, will be only the width, from front limits of highway laws.

When the structure is raised to vertical operating position, the reverse of the above movements of the parts of the structure takes placeand the derrick expands to its full base.dimen- 15 sions, whereupon the superstructure S and cross braces 22 are put in place to complete the structure. It will be evident from the drawings that when the derrick is folded, legs 8-8 project rearwardiy beyond the ends of stringers l and ii a distance equal to the length of girders i3. When the derrick is being raised,- the ends of legs 0 in their downward arc strike the ground before the ends of st ngers I0 and II and this arrang ent provides an upward pry upon legs 8-8 b the ground surface and starts the expansive movement of the structure. Legs 8 are also longer than trusses 9 and extend above the upper ends of the trusses in vertical position, and provide means for more effectively'tying superstructure S to the derrick bas'e structure.

In' the foregoing, the general form of derrick structure described is that of a pyramid, having a rectangular base section, and in which the rear legs 9-4 are in the form of trusses, whose stringers are equal in length and with their base members form isosceles triangles. This form of construction is preferred because of its greater strength and rigidity, and by positioning the transverse pivot bar 4 between the stringers near 40 the base of the structure, a cantilever arrangement is provided which has great strength and readily'lends itself to controlled raising and lowering between transport and operating positions, a very important consideration in the handling 45 of the heavy type derricks referred to above.

It will be understood, however, that the truss construction of the rear legs may be dispensed with and stringers l0 alone with legs 8 used to form the corner legs of the derrick. However,

50 in this case, in order to maintain their parallelism 55 may be useful for handling comparatively light loads, but as indicated, the pyramid construction,

including-the truss construction of legs 8-4, is

preferable under most conditions. I

Derrick structures in accordance with this invention have been constructed having the following specifications:

Over-all height to top of superstructure g 84 feet Height to top of legs 9@ 55 feet Width at base '7-ft.-7 in.

Depth at base (incl. trusses) expanded 15 feet Depth at basefolded 6 ft.-'? in.

Weight (exclusive of S and braces 22) 10,200 lbs. Pipe capacity of derrick'6 inch pip 6,000 feet Numerous modifications and alterations may be made in the size, form and arrangement of details of the derrick structure of this invention without departing from the scope of the appended claim.

What I claim, and desire to secure by Letters Patent is:

In a portable derrick structure, a mobile base,

a derrick mounted on said base adjacent one end thereof, comprising a rear panel positioned transversely of said base and having longitudinal edge members in the form of trusses positionedat right angles to the plane of the rear panel,

each of said truss members comprising front and rear stringers spaced apart at their lower ends panel downwardly against the rear panel comprising a plurality of pivotally mounted girders extending between the longitudinal edges of said front panel and the adjacent truss stringers, whereby when said derrick is moved to transport positionon said base, said front panel will assume a position adjacent to the front stringers of said truss members, with the bottom portion.

of the front panel projecting beyond the ends of the front truss stringers a distance substantially equal to the length of one of the pivoted girders, and when raised to vertical operating position will be spaced from said truss members a distance equal to the length of a girder and means for moving said derrick between transport and vertical operating positions.

mantra, mm. 

